I. Field of the Invention
The present invention relates to phototypesetting machines and, in particular, to a keyboard controlled phototypesetting machine.
II. Description of the Prior Art
For the manufacture of text from the manuscript to the typeset product or printed product, the printing industry uses various phototypesetting installations and machines from manual title typesetting equipment with optical control and keyboard control or directly controlled phototypesetting machines, to phototypesetting machines which are controlled by means of typesetting computers or data carriers, into the so-called CRT high-performance phototypesetting installations with a performance of several millions of symbols per hour. The medium sized phototypesetting machines show a performance of between 50,000 and 250,000 symbols per hour, whereas the performance of the keyboard controlled phototypesetting machines without data carriers is dependent substantially on the speed of the operator.
As far as the directly controlled or keyboard controlled phototypesetting machines are concerned, a substantial number of these machines are used for the so-called exercise work, that is, this is no volume typesetting, such as for books, journals, etc., but individually shaped typesetting with several letter sizes and letter types, such as is necessary for pamphlets, catalogs, forms, etc. The construction of these phototypesetting machines is therefore complicated and expensive with regard to the mechanical and electronical building blocks so they can dispose at any time over a larger supply of symbols of different letter types which are projectable by means of variable optics in the form of various letter sizes. It is an intrinsic quality of these machines, as well as the phototypesetting machines which can be controlled with a data carrier (punch card or magnetic tape), to show a very high degree of flexibility for very different requirements.
III. Prior Art Statement
The aforementioned prior art includes, in the opinion of the applicant, the closest prior art of which applicant is aware.